Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.
Stéphanie K. Schwarting

1 Ludwig-Maximilians-University Munich, Germany - Department of Medicine I, LMU University Hospital
Munich, Germany

2 Ruprecht-Karls-University Heidelberg, Germany - Department of Cardiology, Angiology and Respiratory Medicine, University Hospital
Heidelberg, Germany

Main Body of the Abstract
Background: The coupling between the right ventricle and the pulmonary artery (RV-PAc) describes the right ventricle's ability to adjust to an increased afterload. In addition to pulmonary arterial hypertension (PAH), increased afterload on the RV can result from left ventricular diastolic stiffness caused by the deposition of Transthyretin amyloid (TTR) fibrils. While RV-PAc is a validated prognostic parameter in PAH, its prognostic implication in TTR-cardiomyopathy (ATTR-CM) is unclear.
Objectives: To evaluate the prognostic impact of RV-PAc in ATTR-CM.
Methods/Results: In this multicentre study, RV-PAc was investigated by the echocardiographic surrogate of ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP) in 418 patients with ATTR-CM treated with TTR-stabilizer. The primary endpoint, all-cause mortality, occurred in 11.7% of patients during a mean follow-up of 605 ± 378 days. The RV-PAc ratio emerged as a robust marker for risk stratification with a determined optimal cutoff of 0.382mm/mmHg (AUC 0.73, 95% CI 0.65-0.81) by ROC and Youden’s J analysis. Patients with RV-PAc ratio ≤0.382mm/mmHg (impaired RV-PAc, n=158) exhibited significantly lower survival (HR 4.17, 95% CI 2.21-7.87, p<0.001) than those with RV-Pac ratio >0.382mm/mmHg. In multivariate analysis of echocardiographic parameters, reduced RV-PAc was a strong predictor of mortality (HR 3.2, 95% CI 1.17-6.20, p<0.001).
Conclusion: Impaired adaption of the RV to increased afterload is associated with worse outcome in ATTR-CM patients. RV-PAc ratio can serve as an echocardiographic predictor for all-cause mortality. Therefore, determination of RV-PAc could improve risk stratification for ATTR-CM patients.

**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Stéphanie K. Schwarting

1 Ludwig-Maximilians-University Munich, Germany - Department of Medicine I, LMU University Hospital
Munich, Germany

2 Ruprecht-Karls-University Heidelberg, Germany - Department of Cardiology, Angiology and Respiratory Medicine, University Hospital
Heidelberg, Germany

**Main Body of the Abstract**
**Background:** The coupling between the right ventricle and the pulmonary artery (RV-PAc) describes the right ventricle's ability to adjust to an increased afterload. In addition to pulmonary arterial hypertension (PAH), increased afterload on the RV can result from left ventricular diastolic stiffness caused by the deposition of Transthyretin amyloid (TTR) fibrils. While RV-PAc is a validated prognostic parameter in PAH, its prognostic implication in TTR-cardiomyopathy (ATTR-CM) is unclear.
**Objectives:** To evaluate the prognostic impact of RV-PAc in ATTR-CM.
**Methods/Results:** In this multicentre study, RV-PAc was investigated by the echocardiographic surrogate of ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP) in 418 patients with ATTR-CM treated with TTR-stabilizer. The primary endpoint, all-cause mortality, occurred in 11.7% of patients during a mean follow-up of 605 ± 378 days. The RV-PAc ratio emerged as a robust marker for risk stratification with a determined optimal cutoff of 0.382mm/mmHg (AUC 0.73, 95% CI 0.65-0.81) by ROC and Youden’s J analysis. Patients with RV-PAc ratio ≤0.382mm/mmHg (impaired RV-PAc, n=158) exhibited significantly lower survival (HR 4.17, 95% CI 2.21-7.87, p<0.001) than those with RV-Pac ratio >0.382mm/mmHg. In multivariate analysis of echocardiographic parameters, reduced RV-PAc was a strong predictor of mortality (HR 3.2, 95% CI 1.17-6.20, p<0.001).
**Conclusion:** Impaired adaption of the RV to increased afterload is associated with worse outcome in ATTR-CM patients. RV-PAc ratio can serve as an echocardiographic predictor for all-cause mortality. Therefore, determination of RV-PAc could improve risk stratification for ATTR-CM patients.

RV-PA uncoupling is a strong predictor of mortality in transthyretin amyloid cardiomyopathy. OC8 (#136)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.